CA1222075A - X-ray examination apparatus having a double focusing crystal - Google Patents
X-ray examination apparatus having a double focusing crystalInfo
- Publication number
- CA1222075A CA1222075A CA000446511A CA446511A CA1222075A CA 1222075 A CA1222075 A CA 1222075A CA 000446511 A CA000446511 A CA 000446511A CA 446511 A CA446511 A CA 446511A CA 1222075 A CA1222075 A CA 1222075A
- Authority
- CA
- Canada
- Prior art keywords
- crystal
- double focusing
- jig
- ray
- curvature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
- G01N23/20—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by using diffraction of the radiation by the materials, e.g. for investigating crystal structure; by using scattering of the radiation by the materials, e.g. for investigating non-crystalline materials; by using reflection of the radiation by the materials
- G01N23/207—Diffractometry using detectors, e.g. using a probe in a central position and one or more displaceable detectors in circumferential positions
Landscapes
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Analysing Materials By The Use Of Radiation (AREA)
Abstract
ABSTRACT:
X-ray examination apparatus having a double focusing crystal.
A double focusing monochromator crystal for an X-ray analysis apparatus is formed from a single crystal of silicon or germanium poor in dislocations, in which at a surface coinciding with one of the crystal surfaces of the crystal a cavity is provided. With the accurately finished opposite surface the crystal is preferably secured in a cavity of the jig by means of a glue compound or with the interposition of a metal layer by soldering. More particularly, the cavities are spherical and the ultimate radius of curvature of the crystal is distributed uniformly over the cavity in the crystal and the cavity in the jig.
X-ray examination apparatus having a double focusing crystal.
A double focusing monochromator crystal for an X-ray analysis apparatus is formed from a single crystal of silicon or germanium poor in dislocations, in which at a surface coinciding with one of the crystal surfaces of the crystal a cavity is provided. With the accurately finished opposite surface the crystal is preferably secured in a cavity of the jig by means of a glue compound or with the interposition of a metal layer by soldering. More particularly, the cavities are spherical and the ultimate radius of curvature of the crystal is distributed uniformly over the cavity in the crystal and the cavity in the jig.
Description
P~-IN 10.56~ 1 2.1.19~4 X~ray examination apparatus having a double focusing crysta~
The invention relates to a double focusing X-ray analysis crystal for monochromatization and focusing of X-ray radiation in an g-ray examination apparatus and to an X-ray analysis apparatus provided wit-h such a crystal.
Such an X-ray analysis crys-tal is known from British Patent Specification 1,0~,714. An analysis crystal described therein is c-urved in two directions with different radii of curvature in order to obtain a double focusing The process of bending a crystal into such a form is fairly difficult and in this process the crystal is liable to break or the curvature nevertheless deviates from the envisaged optimum curvature due to a later deformation. In fact, the crystal is constantly in a forced condition, as a result of which deformations are liable to occur during operation, for example, due to temperature variations or ageing phenomena. Further, it is of importance that the back surface of the crystal is not disturbed because irregularities therein may adversely affect the operation of the crystal as a monochronator.
The invention has for its object -to obviate these disadvantages and therefore an X-ray analysis crystal of the kind mentioned in the opening paragraph is characte-rized in that the crystal is a single crystal which is excavated on one side and is arranged with an accurately finished opposite surface in an acc-ura-tely finished cavity of a jig.
It has been found that the use of a single crystal, which has a very stringent Bragg condition and a high reflection with a spherical deformation of the active crystal surface f`or focusing, yields a non-deformable very effective crystal which can be manufac-tured in a compara-tively simple manner.
In a preferred embodiment, the cavities are ~12~2C~7S
PIIN ~0.56~ ~ 2.1.19~4 spherical. The occurrence of irregularities at the back surface can be permanently avoided if 9 before -the crystal is arranged in the jig, surf`ace irregularities are removed from this sllrface, for example, by mechanical processing and/or etching, which is due inter alia -to -the screening effect of the jig.
In a preferred embodiment, the crys-tal is arranged by means oi a glue compound in a jig comprising a material porous to -the glue. More particularly, the jig has a radius of curvature 2R and the active crystal surface has a radius of curvature R. It is possible to provide a planar crystal in the jig and -then to grind the ac-tive surI`ace to -the desired curvature, whilst it is also possible to first provide the crystal with a curvature, 5 which, after the crystal has been mounted in the jig, together with the ^urvature of the jig leads to the desired curvature. Further~ the crystal can be coated on the non-active fla-t side with a layer of metal, which may be applied, for example, by vapour deposi-tion, sputtering or 20 spinning in a layer having a very homogeneous thickness.
1~ith this layer as a joining intermediate layer, the crystal may then be secured again in the jig, for example, by soldering or diffusion, which jig then need not be porous. Alternatively~ the metal layer may be applied in 25 the form of` a metal foil; this is particularly favourable with -the use of a crystal material which in itself is brittle or of low strength. With a metal foil of, for example, phosphor bron~e, a very flexible element of high strength can nevertheless be obtained. The back side of 3C the crystal may also be formed so -that the crys-tal ultimate-ly has an at least s-ubstantially unif`orm -thicknessO The surface of the back side of the crystal sho~lld be very flat because irregularities therein can adversely affect the operation o~ the crystal~
In a further ernbodil~en~, the crystal consists of a sin~le crys~L of sil~o~ or germanium p~or in dis-locations, which, when mounted i~l the jig, is only 7~
I'MN 10.56(~ 3 2.-l.198 elastically clef`ormed. The single ervstal is then, for example, a slice cut along a (124) erystal surface. ~f-ter -the spherical deformation, a centre of eurvature of the (124) crystal surfaces lies on a Rowlancl sphere on which with a close apprcrimation will be located also the centres of` curvatures of the other crystal surfaces, such as, with decreasing crystal surface distances, the (111), (022) and (113) surfaces. As a result, with a single erys-tal in a spectrometer the presence in a specimen to be analysed of elemen-ts having an atomie number between 15 ancl L~o ean be demonstrated by means of, for example, K ~ radiation, whilst by means o-~ Lc~ radiation the presence of elements having a higher atomic number therein can be demonstrated.
In a preferred embodiment according to the in~rention~ the erystal aets as a monochromator in an X-ray analysis apparatus, ~ihereby noi~ for a eomplete analysis a fixed position of the speeimen and two positions of the analysis erystal and a single seanning along the are of a eirele of the deteetor will be suffieient. In this ease, 20 the resolution and the signal-to-noise ratio ean also be materially improved.
The erystal aeeording to the invention ean further be used sueeessfully in, for example, a diffraetometer in whieh, for example~ use is made of a eonverging Cu-l~ ~ 1 25 radiation beam, and in apparatus for stress examination or texture measurements.
A few preferred embodiments aeeorcling to the invention will now be deseribed more fully with referenee to the drawing In the drawing:
~igure I shows a erystal aeeording to the invention as a part of a sphere on whieh the loea-tion of een-tres of eur~ature for distinet erystal surfaees is indiea-ted, Figure 2 shows a erys-tal aeeording to the inven-35 tion at different stages of` manufaeture~
Figures 3~ an~ 3~ show examples of the radia-tion path in an X-ray analy~is appar~us ~r~rided wi-th a silieon single erystal aeeording to the i~vention 7 Z~75 P~IN 10.56S 4 2.1.19~4 Figure 4 shows an outline of a powder dif`fraction apparatus provided with such a crystal, and Firgllre 5 shows an outline of an apparatus for stress examination in ma-terials provided with such a crystal.
Figure 1 shows a silicon single crystal 1 of WiliCh an active surface 3 forms part o-f a sphere 5 on which centres of curv~ture 7 of distinct crys-tal s-urfaces are located~ In the Figure, the centres of curvature for 10 crystal sur~aces (12ll), (-113)~ (022) and (111) for a crystal formed from a slice of material parallel to the (124) crystal surfaces thereof are indicated as such in this configuration, the exact centre of cur-vature fo-r the crystal surfaces (12~) is located on the surface of the sphere and 15 for other groups of crystal surfaces approximate centres of curvature are loca-ted on the surface of -the sphere. The sphere 5, also designated as Rowland sphere, is deterrnined by the position and the radius of curvature of the crystal and the (12ll) centre of curvature. Inter alia the centres of 20 curvature mentioned below are located at least substan-tially on the surface of the sphere in such a manner that -the centres of curvature for the crystal surfaces (113) and (022) are located with the centre of curvature for the crystal surface (124) on the circle circumference of 25 the circle 9 passing through the centre 11 of the sphere 5, while the centre of curvature for the crystal surface (111) is located with the centre of curvature (124) on a circle circumference of a circle 13 orientated at right angles thereto and passing through the centre 11.
Such a crystal is f`ormed by means of a method to be described in Figure 2, in which the startin~ material is a slice 15 of monocrystalline silicon poor in dislocations shown in Figure 2a. Parallel surfaces 17 and 19 of the crystal extend (in this case) parallel to the (124) crystal 35 surf`aces, while in the crystal the crystal surfaces (022) and (113) are indlcated diagramma-tically. At the surface 17, the crys-tal is then excavated~ for example? by grin-~Z~2~75 PIIN 10~G~ 5 2.l. 19~1 ding, until a spherical surface 21 having a radius ofcurvature 2R and shown in Figure 2B is obtained~
A jig 23 shown in Figure 2C and formed in this case from a porous material is correspondingly excavated on one side until a spherical surface 25 is obtained which, for example, also has a radius of curvature 2R.
~ith -the interposition of a glue foil 27, the ground crystal 15 is then pressed into the jig. For this purpose~
use is made here of a diaphragm 29 which is pressed by means of gas or ]iquid pressure against the crystal surface 21 in such a manner tha-t it is loaded atleast substantially homogeneously. In this process 5 it is recornmendable for obtaining a good adherence to heat the assembly to, for example, 180 C and to eliminate the pressure only after cooling. The tempsrature can be adap-ted to the glue and -the excess quantity of glue is absorbed by the porous jig. A combina-tion 30 of crystal and jig thus forned and shown in Figure 2D constitutes a robust element to be readily rnanipulated for X-ray analysis apparatus suiting the purpose. The active surface 21 of the crystal has by a combination of treatments a radius of curvature R which corresponds to that of the sphere 5 in Figure 1.
It will be appreciated tha-t other methods of forming the combination 30 may also be used. ~Iowever, it is required to mount the crystal wi-th adherence at least along its whole circumference and preferably throughout the whole non-active surface 19. As a result, the possibility of later deformation is s-trongly reduced. As already indicated, the crystal may al-ternatively be moun-ted in the jig by soldering with the interposition of a metal layer, whereby irregulari-ties in the layer -thickness of the soldering ma-terial have to be avoided.
Figure 3 shows the radiation path in an X-ray apparatus for analysing a specimen 31 by means of a silicon single crystal 15 thus formed~ Figure 3a shows tlle circle 9 of Figure 1 with the centres of curvature (022), :~Z~Z:~7~
PIIN 10.56~ 6 2 1.1984 (124) and (113), while Figure 3b shows the circle 13 of Figure 1 witll the cen-tres of curvatures (124) and (l11).
Vie~ed from the apparatus, the difference between Figure 3a and Figure 3b is a rotation of the crystal 15 through 90 about an a~is passing through the centre of curvature (124). In dependence upon the wavelength, of ~-ray radiation produced in -the specimen a conical bcam trapped by the crystal is focused by -the crystal in a line on the circle circumference. The cone is determined by -the solid angle viei~ed from the point of intersection of a Bragg condition applying to the relevant crystal surface and the circumference of the crystal. Thus, for example, in Figure 3a, for the element zinc a cone 33 is trapped by the crystal, of which radiation of the wavelength applying to the relevant crystal surfaces, in this case the (113) surfaces, is focused as a conical beam 34 in a line 35 located on the circle 9. ~y means of a detector to be arranged there, the intensity and hence the zinc content in the specimen can be measured. Likewise, radiation of a 2D wavelength characteristic of titanium from a cone 37 is concen-trated by (022) crystal surfaces in the crystal via a conical beam 38 to a line 39 on the circle. In Figure 3b, there is indicated by way of e~ample how after rotation of the crystal the radiation characteristic of 25 the element phosphorus from the cone 4-l is concentrated by (111) crystal surfaces in a conical beam 42 to a line 43 along the circumference of the circle 13. Thus, all -the elements having an atomic number larger than about 15 can be analysed with one of the two positions of the 30 crystal. Use is then made of diffraction a-t the (113), (022) and (1-l1) crys-tal surfaces of the crystal. For the elements having a comparatively low atomic number, use is then made, for example, of K ~ 1 radiation, whilst for the elements having a high atomic num-ber L ~ 1 radiation 35 is used~ Thus, the focus lines for, for e~ample, Ca(20) to Co(27) of K ~ 1 radia-tion diffracted at the (022) crystal surfaces are loca-ted on either side of the poin-t 39, which s also applies to the focus lines for, for example, Sn(51) to Tm(69) of L ~ 1 radiation also diffracted at the (022) crystal surfaces of the crystal.
On either side of the focus point 35, there can be correspondingly measured for Ni(28) to Zr (40) with K ~ 1 radiation at the (113) crystal surfacesand for Yb~70) to U(92) with L ~ 1 radiation at the (113) crystal surfaces. The arrangement is then chosen so that no overlap of the focus lines occurs. If neverthe-less such an overlap should occur, there can be discrimination between elements by, for example, a second measurement with another wave length for the X-ray radiation, for example, K ~ for one of the elements.
A powder diffractometer according to the invention, for which Figure 4 outlines the radiation path, shows a radiation source 51, for example, the target of an anode in an X ray tube, a spherically curved single crystal 53, a specimen 55 in transmis-sion position and a specimen 57 in reflection position. The source 51 and the crystal 53 are located on a Rowland sphere 60, on which a focus 62 of an X-ray beam 64 focused by the crystal is also located. The X-ray radiation is, for example, copper K ~ 1 radiation. In an arrangement of the kind shown here, radiation diffracted at distinct crystal surfaces of the speciman 55 is focused by transmission in distinct focus lines 61 and 63 on the circumference of a focus sphere 66. For reflection, radiation diffracted at distinct crystal surfaces of the specimen is focused in focus lines 65 and 67 on the circumference of a focus sphere 68. With detectors 69 moving along these spheres or with position-sensitive detectors mounted along these spheres, the local 7a 20104-7605 intensity may now again be measured simultaneously for transmis-sion and reflection. With a movement mechanism described in the co-pending Canadian Patent Application Serial No. 446,510 filed on February 1, 1984 by the applicant, the specimen can be displaced within the beam path through a distance equal to twice the diameter of the sphere 66 in a correct angular relationship.
~z~
PIIN 10.568 8 2.1.1~84 ~n X-ray analysis apparatus clesigned for measuring macro-s~resses in, for exa.mple, work pieces provided witll a crystal according to the invention, comprises, as shown in Figure 5, an X-ray source 70, a 5 spherical analysis crys-tal 72, a specirnen 7~ with, for example, crystal surfaces 76 and a, for exa~ple, J
position-sensitive detector 78 by which th.e racliation in-tensity can be measured as a function of` the deflection angle. The source 70, the crystal 72 and the beam focus lO 80 of an X-ray beam 82 are located on a Rowland sphere 8l4.
Similarly~ the beam focus 80, an irradiated specimen surface 86 and a focus line 88 of a diffracted beam 92 are located on a Rowland sphere 96. The focus line 88 applying to, for example, a specirnen or a direction in a specimen '.
lS in which IlO macro-stresses are present, shifts to a focus line 90 for a specimen or a direction in a specimen in which macro-stresses are presen-t. The arc distance between the focus line 88 and the focus line 90 is a measure for the value of the macro-stresses in the specimen measured 20 in a given crystal direction. This value can be measured by exchange of specimens, whereby, for example~ in order to determine the position of the focus line 88, first a stress-free specimen is measured and then specimens with unknown macro-stresses are measured. Further, a specimen 25 can be rotated before the neasurement, whereby either by an additional measurernent or by an iteration process the position of a focus line of a stress-free measurement can be determined with the measurement results.
The invention relates to a double focusing X-ray analysis crystal for monochromatization and focusing of X-ray radiation in an g-ray examination apparatus and to an X-ray analysis apparatus provided wit-h such a crystal.
Such an X-ray analysis crys-tal is known from British Patent Specification 1,0~,714. An analysis crystal described therein is c-urved in two directions with different radii of curvature in order to obtain a double focusing The process of bending a crystal into such a form is fairly difficult and in this process the crystal is liable to break or the curvature nevertheless deviates from the envisaged optimum curvature due to a later deformation. In fact, the crystal is constantly in a forced condition, as a result of which deformations are liable to occur during operation, for example, due to temperature variations or ageing phenomena. Further, it is of importance that the back surface of the crystal is not disturbed because irregularities therein may adversely affect the operation of the crystal as a monochronator.
The invention has for its object -to obviate these disadvantages and therefore an X-ray analysis crystal of the kind mentioned in the opening paragraph is characte-rized in that the crystal is a single crystal which is excavated on one side and is arranged with an accurately finished opposite surface in an acc-ura-tely finished cavity of a jig.
It has been found that the use of a single crystal, which has a very stringent Bragg condition and a high reflection with a spherical deformation of the active crystal surface f`or focusing, yields a non-deformable very effective crystal which can be manufac-tured in a compara-tively simple manner.
In a preferred embodiment, the cavities are ~12~2C~7S
PIIN ~0.56~ ~ 2.1.19~4 spherical. The occurrence of irregularities at the back surface can be permanently avoided if 9 before -the crystal is arranged in the jig, surf`ace irregularities are removed from this sllrface, for example, by mechanical processing and/or etching, which is due inter alia -to -the screening effect of the jig.
In a preferred embodiment, the crys-tal is arranged by means oi a glue compound in a jig comprising a material porous to -the glue. More particularly, the jig has a radius of curvature 2R and the active crystal surface has a radius of curvature R. It is possible to provide a planar crystal in the jig and -then to grind the ac-tive surI`ace to -the desired curvature, whilst it is also possible to first provide the crystal with a curvature, 5 which, after the crystal has been mounted in the jig, together with the ^urvature of the jig leads to the desired curvature. Further~ the crystal can be coated on the non-active fla-t side with a layer of metal, which may be applied, for example, by vapour deposi-tion, sputtering or 20 spinning in a layer having a very homogeneous thickness.
1~ith this layer as a joining intermediate layer, the crystal may then be secured again in the jig, for example, by soldering or diffusion, which jig then need not be porous. Alternatively~ the metal layer may be applied in 25 the form of` a metal foil; this is particularly favourable with -the use of a crystal material which in itself is brittle or of low strength. With a metal foil of, for example, phosphor bron~e, a very flexible element of high strength can nevertheless be obtained. The back side of 3C the crystal may also be formed so -that the crys-tal ultimate-ly has an at least s-ubstantially unif`orm -thicknessO The surface of the back side of the crystal sho~lld be very flat because irregularities therein can adversely affect the operation o~ the crystal~
In a further ernbodil~en~, the crystal consists of a sin~le crys~L of sil~o~ or germanium p~or in dis-locations, which, when mounted i~l the jig, is only 7~
I'MN 10.56(~ 3 2.-l.198 elastically clef`ormed. The single ervstal is then, for example, a slice cut along a (124) erystal surface. ~f-ter -the spherical deformation, a centre of eurvature of the (124) crystal surfaces lies on a Rowlancl sphere on which with a close apprcrimation will be located also the centres of` curvatures of the other crystal surfaces, such as, with decreasing crystal surface distances, the (111), (022) and (113) surfaces. As a result, with a single erys-tal in a spectrometer the presence in a specimen to be analysed of elemen-ts having an atomie number between 15 ancl L~o ean be demonstrated by means of, for example, K ~ radiation, whilst by means o-~ Lc~ radiation the presence of elements having a higher atomic number therein can be demonstrated.
In a preferred embodiment according to the in~rention~ the erystal aets as a monochromator in an X-ray analysis apparatus, ~ihereby noi~ for a eomplete analysis a fixed position of the speeimen and two positions of the analysis erystal and a single seanning along the are of a eirele of the deteetor will be suffieient. In this ease, 20 the resolution and the signal-to-noise ratio ean also be materially improved.
The erystal aeeording to the invention ean further be used sueeessfully in, for example, a diffraetometer in whieh, for example~ use is made of a eonverging Cu-l~ ~ 1 25 radiation beam, and in apparatus for stress examination or texture measurements.
A few preferred embodiments aeeorcling to the invention will now be deseribed more fully with referenee to the drawing In the drawing:
~igure I shows a erystal aeeording to the invention as a part of a sphere on whieh the loea-tion of een-tres of eur~ature for distinet erystal surfaees is indiea-ted, Figure 2 shows a erys-tal aeeording to the inven-35 tion at different stages of` manufaeture~
Figures 3~ an~ 3~ show examples of the radia-tion path in an X-ray analy~is appar~us ~r~rided wi-th a silieon single erystal aeeording to the i~vention 7 Z~75 P~IN 10.56S 4 2.1.19~4 Figure 4 shows an outline of a powder dif`fraction apparatus provided with such a crystal, and Firgllre 5 shows an outline of an apparatus for stress examination in ma-terials provided with such a crystal.
Figure 1 shows a silicon single crystal 1 of WiliCh an active surface 3 forms part o-f a sphere 5 on which centres of curv~ture 7 of distinct crys-tal s-urfaces are located~ In the Figure, the centres of curvature for 10 crystal sur~aces (12ll), (-113)~ (022) and (111) for a crystal formed from a slice of material parallel to the (124) crystal surfaces thereof are indicated as such in this configuration, the exact centre of cur-vature fo-r the crystal surfaces (12~) is located on the surface of the sphere and 15 for other groups of crystal surfaces approximate centres of curvature are loca-ted on the surface of -the sphere. The sphere 5, also designated as Rowland sphere, is deterrnined by the position and the radius of curvature of the crystal and the (12ll) centre of curvature. Inter alia the centres of 20 curvature mentioned below are located at least substan-tially on the surface of the sphere in such a manner that -the centres of curvature for the crystal surfaces (113) and (022) are located with the centre of curvature for the crystal surface (124) on the circle circumference of 25 the circle 9 passing through the centre 11 of the sphere 5, while the centre of curvature for the crystal surface (111) is located with the centre of curvature (124) on a circle circumference of a circle 13 orientated at right angles thereto and passing through the centre 11.
Such a crystal is f`ormed by means of a method to be described in Figure 2, in which the startin~ material is a slice 15 of monocrystalline silicon poor in dislocations shown in Figure 2a. Parallel surfaces 17 and 19 of the crystal extend (in this case) parallel to the (124) crystal 35 surf`aces, while in the crystal the crystal surfaces (022) and (113) are indlcated diagramma-tically. At the surface 17, the crys-tal is then excavated~ for example? by grin-~Z~2~75 PIIN 10~G~ 5 2.l. 19~1 ding, until a spherical surface 21 having a radius ofcurvature 2R and shown in Figure 2B is obtained~
A jig 23 shown in Figure 2C and formed in this case from a porous material is correspondingly excavated on one side until a spherical surface 25 is obtained which, for example, also has a radius of curvature 2R.
~ith -the interposition of a glue foil 27, the ground crystal 15 is then pressed into the jig. For this purpose~
use is made here of a diaphragm 29 which is pressed by means of gas or ]iquid pressure against the crystal surface 21 in such a manner tha-t it is loaded atleast substantially homogeneously. In this process 5 it is recornmendable for obtaining a good adherence to heat the assembly to, for example, 180 C and to eliminate the pressure only after cooling. The tempsrature can be adap-ted to the glue and -the excess quantity of glue is absorbed by the porous jig. A combina-tion 30 of crystal and jig thus forned and shown in Figure 2D constitutes a robust element to be readily rnanipulated for X-ray analysis apparatus suiting the purpose. The active surface 21 of the crystal has by a combination of treatments a radius of curvature R which corresponds to that of the sphere 5 in Figure 1.
It will be appreciated tha-t other methods of forming the combination 30 may also be used. ~Iowever, it is required to mount the crystal wi-th adherence at least along its whole circumference and preferably throughout the whole non-active surface 19. As a result, the possibility of later deformation is s-trongly reduced. As already indicated, the crystal may al-ternatively be moun-ted in the jig by soldering with the interposition of a metal layer, whereby irregulari-ties in the layer -thickness of the soldering ma-terial have to be avoided.
Figure 3 shows the radiation path in an X-ray apparatus for analysing a specimen 31 by means of a silicon single crystal 15 thus formed~ Figure 3a shows tlle circle 9 of Figure 1 with the centres of curvature (022), :~Z~Z:~7~
PIIN 10.56~ 6 2 1.1984 (124) and (113), while Figure 3b shows the circle 13 of Figure 1 witll the cen-tres of curvatures (124) and (l11).
Vie~ed from the apparatus, the difference between Figure 3a and Figure 3b is a rotation of the crystal 15 through 90 about an a~is passing through the centre of curvature (124). In dependence upon the wavelength, of ~-ray radiation produced in -the specimen a conical bcam trapped by the crystal is focused by -the crystal in a line on the circle circumference. The cone is determined by -the solid angle viei~ed from the point of intersection of a Bragg condition applying to the relevant crystal surface and the circumference of the crystal. Thus, for example, in Figure 3a, for the element zinc a cone 33 is trapped by the crystal, of which radiation of the wavelength applying to the relevant crystal surfaces, in this case the (113) surfaces, is focused as a conical beam 34 in a line 35 located on the circle 9. ~y means of a detector to be arranged there, the intensity and hence the zinc content in the specimen can be measured. Likewise, radiation of a 2D wavelength characteristic of titanium from a cone 37 is concen-trated by (022) crystal surfaces in the crystal via a conical beam 38 to a line 39 on the circle. In Figure 3b, there is indicated by way of e~ample how after rotation of the crystal the radiation characteristic of 25 the element phosphorus from the cone 4-l is concentrated by (111) crystal surfaces in a conical beam 42 to a line 43 along the circumference of the circle 13. Thus, all -the elements having an atomic number larger than about 15 can be analysed with one of the two positions of the 30 crystal. Use is then made of diffraction a-t the (113), (022) and (1-l1) crys-tal surfaces of the crystal. For the elements having a comparatively low atomic number, use is then made, for example, of K ~ 1 radiation, whilst for the elements having a high atomic num-ber L ~ 1 radiation 35 is used~ Thus, the focus lines for, for e~ample, Ca(20) to Co(27) of K ~ 1 radia-tion diffracted at the (022) crystal surfaces are loca-ted on either side of the poin-t 39, which s also applies to the focus lines for, for example, Sn(51) to Tm(69) of L ~ 1 radiation also diffracted at the (022) crystal surfaces of the crystal.
On either side of the focus point 35, there can be correspondingly measured for Ni(28) to Zr (40) with K ~ 1 radiation at the (113) crystal surfacesand for Yb~70) to U(92) with L ~ 1 radiation at the (113) crystal surfaces. The arrangement is then chosen so that no overlap of the focus lines occurs. If neverthe-less such an overlap should occur, there can be discrimination between elements by, for example, a second measurement with another wave length for the X-ray radiation, for example, K ~ for one of the elements.
A powder diffractometer according to the invention, for which Figure 4 outlines the radiation path, shows a radiation source 51, for example, the target of an anode in an X ray tube, a spherically curved single crystal 53, a specimen 55 in transmis-sion position and a specimen 57 in reflection position. The source 51 and the crystal 53 are located on a Rowland sphere 60, on which a focus 62 of an X-ray beam 64 focused by the crystal is also located. The X-ray radiation is, for example, copper K ~ 1 radiation. In an arrangement of the kind shown here, radiation diffracted at distinct crystal surfaces of the speciman 55 is focused by transmission in distinct focus lines 61 and 63 on the circumference of a focus sphere 66. For reflection, radiation diffracted at distinct crystal surfaces of the specimen is focused in focus lines 65 and 67 on the circumference of a focus sphere 68. With detectors 69 moving along these spheres or with position-sensitive detectors mounted along these spheres, the local 7a 20104-7605 intensity may now again be measured simultaneously for transmis-sion and reflection. With a movement mechanism described in the co-pending Canadian Patent Application Serial No. 446,510 filed on February 1, 1984 by the applicant, the specimen can be displaced within the beam path through a distance equal to twice the diameter of the sphere 66 in a correct angular relationship.
~z~
PIIN 10.568 8 2.1.1~84 ~n X-ray analysis apparatus clesigned for measuring macro-s~resses in, for exa.mple, work pieces provided witll a crystal according to the invention, comprises, as shown in Figure 5, an X-ray source 70, a 5 spherical analysis crys-tal 72, a specirnen 7~ with, for example, crystal surfaces 76 and a, for exa~ple, J
position-sensitive detector 78 by which th.e racliation in-tensity can be measured as a function of` the deflection angle. The source 70, the crystal 72 and the beam focus lO 80 of an X-ray beam 82 are located on a Rowland sphere 8l4.
Similarly~ the beam focus 80, an irradiated specimen surface 86 and a focus line 88 of a diffracted beam 92 are located on a Rowland sphere 96. The focus line 88 applying to, for example, a specirnen or a direction in a specimen '.
lS in which IlO macro-stresses are present, shifts to a focus line 90 for a specimen or a direction in a specimen in which macro-stresses are presen-t. The arc distance between the focus line 88 and the focus line 90 is a measure for the value of the macro-stresses in the specimen measured 20 in a given crystal direction. This value can be measured by exchange of specimens, whereby, for example~ in order to determine the position of the focus line 88, first a stress-free specimen is measured and then specimens with unknown macro-stresses are measured. Further, a specimen 25 can be rotated before the neasurement, whereby either by an additional measurernent or by an iteration process the position of a focus line of a stress-free measurement can be determined with the measurement results.
Claims (10)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A double focusing X-ray analysis crystal for mono-chromatization and focusing of X-ray radiation in an X-ray analysis apparatus, characterized in that the crystal is a single crystal which is excavated on one side and is arranged with an opposite accurately finished surface in an accurately finished cavity of a jig.
2. A double focusing crystal as claimed in claim 1, char-acterized in that both the cavity in the crystal and that in the jig are spherical.
3. A double focusing crystal as claimed in claim 1, char-acterized in that it is secured by means of a glue compound over at least substantially the whole relevant surface in a jig having glue-absorbing properties.
4. A double focusing X-ray analysis crystal as claimed in claim 1, characterized in that it is secured in the jig with the interposition of a metal layer provided on the crystal and having an accurately defined thickness.
5. A double focusing crystal as claimed in claim 2, 3 or 4, characterized in that the spherical cavity of the jig has a radius of curvature which is at least approximately equal to twice the radius of curvature of an excavated crystal secured therein.
6. A double focusing crystal as claimed in claim 1, 2 or 3, characterized in that it is formed from a plane-parallel slice of silicon or germanium poor in dislocations, the parallel end faces of which coincide with crystal surfaces.
7. A double focusing crystal as claimed in claim 1, 2 or 3, characterized in that the opposite surface of the crystal is formed in such a manner that the excavated crystal arranged in the jig has at least substantially a homogeneous thickness.
8. An X-ray diffractometer, characterized in that it is provided with a monochromator comprising a double focusing analy-sis crystal as claimed in claim 1, 2 or 3.
9. An X-ray spectrometer, characterized in that it is pro-vided with a double focusing analysis crystal as claimed in claim 1, 2 or 3.
10. An X-ray analysis apparatus for measuring macro-stresses in materials, characterized in that it is provided with a double focusing analysis crystal as claimed in claim 1, 2 or 3.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL8300421A NL8300421A (en) | 1983-02-04 | 1983-02-04 | ROENTGEN RESEARCH DEVICE WITH DOUBLE FOCUSING CRYSTAL. |
| NL8300421 | 1983-02-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1222075A true CA1222075A (en) | 1987-05-19 |
Family
ID=19841350
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000446511A Expired CA1222075A (en) | 1983-02-04 | 1984-02-01 | X-ray examination apparatus having a double focusing crystal |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0115892B1 (en) |
| JP (1) | JPS59153152A (en) |
| CA (1) | CA1222075A (en) |
| DE (1) | DE3465519D1 (en) |
| NL (1) | NL8300421A (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL8501181A (en) * | 1985-04-24 | 1986-11-17 | Philips Nv | CRYSTAL FOR A ROENT GENAL ANALYSIS DEVICE. |
| JPS62141730U (en) * | 1986-02-28 | 1987-09-07 | ||
| WO1996034274A2 (en) * | 1995-04-26 | 1996-10-31 | Philips Electronics N.V. | Method of manufacturing an x-ray optical element for an x-ray analysis apparatus |
| FR2841371B1 (en) * | 2002-06-19 | 2004-10-22 | Xenocs | OPTICAL ASSEMBLY AND ASSOCIATED METHOD |
| DE20320792U1 (en) | 2002-06-19 | 2005-05-04 | Xenocs | Optical arrangement and associated device |
| CN107024493A (en) * | 2017-03-20 | 2017-08-08 | 中国工程物理研究院电子工程研究所 | A kind of method of testing of silicon carbide single crystal wafer base plane bending |
| CN114649106B (en) * | 2022-03-17 | 2024-08-27 | 重庆大学 | Spherical high-energy transmission crystal imager and manufacturing method |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL6410514A (en) * | 1964-09-10 | 1966-03-11 | ||
| JPS454549Y1 (en) * | 1968-10-11 | 1970-03-02 | ||
| JPS5023994A (en) * | 1973-07-02 | 1975-03-14 | ||
| US3927319A (en) * | 1974-06-28 | 1975-12-16 | Univ Southern California | Crystal for X-ray crystal spectrometer |
| US4078175A (en) * | 1976-09-20 | 1978-03-07 | Nasa | Apparatus for use in examining the lattice of a semiconductor wafer by X-ray diffraction |
| DD149420A1 (en) * | 1980-03-03 | 1981-07-08 | Reinhard Arnhold | X-ray diffractometer |
-
1983
- 1983-02-04 NL NL8300421A patent/NL8300421A/en not_active Application Discontinuation
-
1984
- 1984-02-01 CA CA000446511A patent/CA1222075A/en not_active Expired
- 1984-02-01 EP EP19840200132 patent/EP0115892B1/en not_active Expired
- 1984-02-01 DE DE8484200132T patent/DE3465519D1/en not_active Expired
- 1984-02-03 JP JP59017218A patent/JPS59153152A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| NL8300421A (en) | 1984-09-03 |
| JPS59153152A (en) | 1984-09-01 |
| DE3465519D1 (en) | 1987-09-24 |
| JPH0557536B2 (en) | 1993-08-24 |
| EP0115892A1 (en) | 1984-08-15 |
| EP0115892B1 (en) | 1987-08-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7076024B2 (en) | X-ray apparatus with dual monochromators | |
| US4561062A (en) | Stress measurement by X-ray diffractometry | |
| US4599741A (en) | System for local X-ray excitation by monochromatic X-rays | |
| US5406609A (en) | X-ray analysis apparatus | |
| US5414747A (en) | Method and apparatus for in-process analysis of polycrystalline films and coatings by x-ray diffraction | |
| US5745543A (en) | Apparatus for simultaneous X-ray diffraction and X-ray fluorescence measurements | |
| US5509043A (en) | Asymmetrical 4-crystal monochromator | |
| Allen et al. | Measurement of internal stress within bulk materials using neutron diffraction | |
| US5132997A (en) | X-ray spectroscopic analyzing apparatus | |
| EP0110469B1 (en) | X-ray analysis apparatus comprising a four-crystal monochromator | |
| CA1222075A (en) | X-ray examination apparatus having a double focusing crystal | |
| JP2006194888A (en) | Instrument for measuring in-situ temperature using x-ray diffusion | |
| JP2001021507A (en) | Xafs measuring apparatus | |
| JPH1114561A (en) | Apparatus and method for measurement of x-rays | |
| US6516047B2 (en) | X-ray diffraction apparatus and method | |
| JP2940757B2 (en) | X-ray diffraction analyzer | |
| JP4160124B2 (en) | X-ray spectrometer having an analyzer crystal having a partially varying and partially constant radius of curvature | |
| JP2000155102A (en) | X-ray measuring apparatus and method therefor | |
| JP2952284B2 (en) | X-ray optical system evaluation method | |
| Dhez et al. | Tests Of Short Period X-Ray Multilayer Mirrors Using A Position Sensitive Proportional Counter | |
| JPH04164239A (en) | Powder x-ray diffraction meter | |
| JP2003014894A (en) | X-ray spectroscopic method and x-ray spectroscopic device | |
| JPH09113468A (en) | Method for measuring positive extreme point chart | |
| CA1195786A (en) | Stress measurement by x-ray diffractometry | |
| Winegar | Measurement of crystallographic texture at chalk river nuclear laboratories |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |